For the video promo for her song “Chase the Thrill,” Nikka Costa said she and the director “just got in my bathroom and went for it.”

Lest you think that something dirty happened, “went for it” in this case means re-creating the famous shower scene from Psycho, with Costa in the role of Marion Crane.

Also on her “Nikka’s Box” YouTube channel (YouTube.com/user/nikkasbox) is a Rocky-style training video and “Streaking Nikka,” in which the topless rock/soul singer (naughty bits obscured) encourages viewers to check out her new EP Pro*Whoa. “What’s a girl gotta do to get her music heard?” she asks.

Such is the existence of Costa, who will close River Roots Live with an 11 p.m. set on August 20. She is now operating independently after a successful music career as a child (she is the daughter of producer Don Costa) and well-reviewed albums as an adult on Virgin and Stax. (Entertainment Weekly called 2001’s Everybody Got Their Something an “intoxicating starburst of self-affirming R&B” and “an audacious, fresh-as-a-daisy debut,” while the All Music Guide said its follow-up features songs that are “muscular, funky, and imaginatively arranged ... .This is big, dynamic music that cries for a big audience ... .”)

“You can’t really get more independent than I am right now,” the 39-year-old said in a phone interview last week. “That is for sure.”

Pro*Whoa was originally intended as a full-length, but Costa parted ways with EMI and its release was scrapped. “We just had an opportunity to re-tool it and re-tool our game plan, because we knew we were going to do it independently,” she said. “So it kind of gave us the opportunity to play with the formula of record-releasing.”

The EP is a solid nugget of danceable electro-rock, a stark and sometimes aggressive departure from the straight soul of 2008’s Pebble to a Pearl. Opener “Head First” and closer “Chase the Thrill” have a patient tension, and “Never Wanna C U Again” and “Stuff” are slinky, bright, and catchy.

“Nylons in a Rip” draws anger from frustration, but it’s the title track – a verbal smackdown in which the singer raps convincingly – that showcases Costa’s versatility. “To me it really didn’t feel like I was dipping my toe into an area I’d never gone before,” she said of the EP’s tone. “Except for the rap part. That I’d never done. And I thought I would never do. But I was trying to spread my wings a little bit and experiment with some other stuff. ... It’s kind of balls to the wall, but in a different way. Not wailing over a big rock track, but talking shit over a track.”

Freed of label machinery, Costa’s manager suggested weekly videos to promote the EP. “It was a really good way to kind of still be an artist but also show my personality,” she said. “I have a very dorky side, but when I’m doing my music, I’m very serious about it, and it’s all like bad-ass and whatever. And so it [the YouTube channel] was nice to have another outlet showing my dorky side.”

And she said that tools such as YouTube, Facebook, and Twitter foster a direct relationship with her fans. “It really just brought me closer to my audience,” she said. She reads comments and takes requests – a departure from her days with labels: “There’s you, and there’s the major label sitting right in the middle of you and audience, and a lot of times you don’t get that conversation going.”

Costa now hopes to release three or four EPs a year instead of the traditional album. “I have different playlists of different genres,” she explained. “And I want cohesive records. So I have to just take which one I want to explore at the time.”

Working without label support – both creative and financial – is a challenge, she said: “I don’t have a lot of money. To float this kind of upstart business is a little stressful sometimes, but the payoff is having real creative freedom and a sense of we can do whatever, so let’s do it, let’s try it ... . It’s a very why-not place to be. Which is liberating. So the payoff is okay.”

Costa said that Prince has encouraged her for years to go the independent route. “You have to be ready to take it on, and you have to be willing to have it kind of tough for a minute,” she said. “It’s very different from having a record company behind you and pushing you and throwing money at a project. Everything is a little bit more of a struggle, and a little bit more of a fight. ...

“It’s been tough for a while, and I’m doing what I can to keep moving in the mud. ... Even when I was on a major label, I was in the mud.”